14 years old - Didn't really know what I was getting myself into.
16 years old - A fling.
18 years old - I was more interested in partying and being with my friends.
20 years old - A fling.
22 years old - A fling.
24 years old - Very explosive relationship. The sex and the breakup in particular.

Haven't been in a relationship since that last one because it really weakened me.

None. I didn't have any interest in high school or college, still don't really. Even if I were to pursue a potential relationship between working full time, various obligations outside work, and my own interests I don't have much time. So it probably wouldn't work.

To be honest, even when it comes up in conversation with a girlfriend I will reply that the only relationship I care about is the one I am in now. If that is not good enough for her, and the knowledge that I clearly am not going to be talking about that relationship to anyone later, then that is her problem not mine.

Clean VD tests are so that neither side needs to say how many lovers they have had.